\tracingonline=2
\tracingcommands=2
\tracingmacros=2
\tracingrestores=2

\catcode`{=1
\catcode`}=2

\count\number--1=10
\showthe\count1

\number\relax

\newlinechar=`@
\message{~ \number--25@}
\message{~ \number-25@}
\message{~ \number\count1@}

\message{~ \romannumeral--25@}
\message{~ \romannumeral-25@}
\message{~ \romannumeral\count1@}

% double expansion
\message{~ \number\number--25@}
\message{~ \number\number-25@}
\message{~ \number\number\count1@}
\message{~ \number\number\count\number1@}

\end
